1. Field of the Invention
The present invention relates to a copying apparatus, and more particularly, to a copying apparatus provided with an automatic document feeder
2. Description of the Related Art
In recent years, there has been a growing demand for automatic paper handling devices in carrying out a copying operation. In order to meet the demand, various types of auxiliary devices of a copying apparatus have been developed and put to practical use. For example, one of such auxiliary devices is an automatic document feeder which automatically feeds original documents one by one to the copying apparatus.
According to a known automatic document feeder, a set of originals comprising one original document or more placed on an original document-placing tray is sequentially fed to an exposure position until the last one of original documents has been fed thereto, and then, discharged from the exposure position.
During such operation, it is not enabled that a copying condition such as the number of sheets to be copied, copy magnification or the like may be changed. When a plurality of different sets of originals are copied, at first, one set of originals set on the tray is copied with the automatic document feeder, thereafter, another set of originals must be copied with the feeder, and so on. Such an operation takes much time.
Consequently, in order to avoid the above-mentioned operation, it is considered that a plurality of sets of originals are set on the original document-placing tray at the same time and, thereafter, a copying operation is carried out sequentially with one starting operation, and if necessary, with changing the copy conditions corresponding to each of the sets of originals. To that end, the following procedure has been proposed, conventionally. That is, the number of original documents included in each of the sets of originals is pre-inputted and various kinds of controls are executed on the basis of the number of original documents which are fed by the automatic document feeder. In this respect, an operator had to count the number of original documents at every case and to input such data. In addition, the inputting operation itself is complicated.
There are other methods or devices available in addition to those described above. That is, one is that a special sheet as being a marker is inserted between sets of originals as disclosed in Japanese Patent Laid-open Publication No. 57-181559 (1982), and the other is that a first original document for each of the sets of originals has optical information for instructing special instructions and a copying operation mode is decided by reading the information thereof. However, a reading means for reading this information given in the mark sheet is necessary to these methods or devices. Furthermore, control of such mark sheets is troublesome.